Sweet Potato Varietal Selection Using Combined Methods of Multi-Trait Index, Genetic Gain and Stability from Multi-Environmental Evaluations

Abstract

Adaptation to several environmental conditions is a challenge for breeders for producing new varieties. Breeders select genotypes which show higher performance according to desired traits compared to the average of a large segregant population. In several crops, the selection index is mainly based on traits such as yield, quality, adequate plant architecture, etc. Therefore, multi-trait selection allows for the identification of genotypes that integrally exhibit a better profile and stability, in addition to the dissection of promising varieties based on their superiority in an evaluated population. In this paper, a multi-trait index included in an R tool named CropInd was used to estimate the agronomic performance of 19 sweet potato genotypes in multi-environmental evaluations (three cycles and eight locations). Here, the multi-trait index incorporated variables such as total and commercial fresh root yield, along with survival percentage, which were used in this study. Simultaneously, stability and genetic gain analysis were included to select superior sweet potato genotypes. Results showed that the CropInd script is a suitable and convenient tool for genotype selection based on multi-trait and multi-environmental data. Indexes for specific environment and general behavior (combining multi-environments) were the main output used for genotype selection. Multi-trait selection index, stability, and genetic gain analysis assisted the phenotypic selection performed by breeders. This study resulted in the selection of 0113-672COR as new variety for the Colombian Caribbean region due to its multi-trait performance and stability.

Keywords

• genotype by environment interaction
• selection index
• phenotype
• plant breeding